[PATCH v3 1/9] PM / Domains: Add dev_pm_domain_get|put() APIs
From: Ulf Hansson <hidden>
Date: 2014-10-13 14:02:02
Also in:
linux-pm, linux-samsung-soc
Subsystem:
driver core, kobjects, debugfs and sysfs, generic pm domains, hibernation (aka software suspend, aka swsusp), power management core, suspend to ram, the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Ulf Hansson, Linus Torvalds
There may be more than one device in a PM domain which then will be probed at different points in time. Depending on timing and runtime PM support, in for the device related driver/subsystem, a PM domain may be advised to power off after a successful probe sequence. A general requirement for a device within a PM domain, is that the PM domain must stay powered during the probe sequence. To cope with such requirement, let's add the dev_pm_domain_get|put() APIs. These APIs are intended to be invoked from subsystem-level code and the calls between get/put needs to be balanced. dev_pm_domain_get(), tells the PM domain that it needs to increase a usage count and to keep supplying power. dev_pm_domain_put(), does the opposite. For a PM domain to support this feature, it must implement the optional ->get|put() callbacks. Signed-off-by: Ulf Hansson <redacted> --- drivers/base/power/common.c | 40 ++++++++++++++++++++++++++++++++++++++++ include/linux/pm.h | 2 ++ include/linux/pm_domain.h | 4 ++++ 3 files changed, 46 insertions(+)
diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c
index b0f1388..b4f0c8c 100644
--- a/drivers/base/power/common.c
+++ b/drivers/base/power/common.c@@ -134,3 +134,43 @@ void dev_pm_domain_detach(struct device *dev, bool power_off) dev->pm_domain->detach(dev, power_off); } EXPORT_SYMBOL_GPL(dev_pm_domain_detach); + +/** + * dev_pm_domain_get - Increase usage count to keep a PM domain powered. + * @domain: The PM domain to operate on. + * + * This function will not by itself increase the usage count, that's up to each + * PM domain implementation to support. Typically it should be invoked from + * subsystem level code prior drivers starts probing. + * + * Do note, it's optional to implement the ->get() callback for a PM domain. + * + * Returns 0 on successfully increased usage count or negative error code. + */ +int dev_pm_domain_get(struct dev_pm_domain *domain) +{ + int ret = 0; + + if (domain && domain->get) + ret = domain->get(domain); + + return ret; +} +EXPORT_SYMBOL_GPL(dev_pm_domain_get); + +/** + * dev_pm_domain_put - Decrease usage count to allow a PM domain to power off. + * @domain: The PM domain to operate on. + * + * This function will not by itself decrease the usage count, that's up to each + * PM domain implementation to support. Typically it should be invoked from + * subsystem level code after drivers has finished probing. + * + * Do note, it's optional to implement the ->put() callback for a PM domain. + */ +void dev_pm_domain_put(struct dev_pm_domain *domain) +{ + if (domain && domain->put) + domain->put(domain); +} +EXPORT_SYMBOL_GPL(dev_pm_domain_put);
diff --git a/include/linux/pm.h b/include/linux/pm.h
index 383fd68..f71900d 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h@@ -620,6 +620,8 @@ extern int dev_pm_put_subsys_data(struct device *dev); struct dev_pm_domain { struct dev_pm_ops ops; void (*detach)(struct device *dev, bool power_off); + int (*get)(struct dev_pm_domain *domain); + void (*put)(struct dev_pm_domain *domain); }; /*
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 73e938b..8e2806f 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h@@ -304,12 +304,16 @@ static inline int of_genpd_add_provider_onecell(struct device_node *np, #ifdef CONFIG_PM extern int dev_pm_domain_attach(struct device *dev, bool power_on); extern void dev_pm_domain_detach(struct device *dev, bool power_off); +extern int dev_pm_domain_get(struct dev_pm_domain *domain); +extern void dev_pm_domain_put(struct dev_pm_domain *domain); #else static inline int dev_pm_domain_attach(struct device *dev, bool power_on) { return -ENODEV; } static inline void dev_pm_domain_detach(struct device *dev, bool power_off) {} +static inline int dev_pm_domain_get(struct dev_pm_domain *domain) { return 0; } +static inline void dev_pm_domain_put(struct dev_pm_domain *domain) {} #endif #endif /* _LINUX_PM_DOMAIN_H */
--
1.9.1